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409,000 Miles Without An Oil Change

Read the documented field test: one truck, one set of AMSOIL protection, and 409,000 miles of continuous oil.

As Wear-Free as a Brand-New Engine

After 409,000 miles without an oil change, the AMSOIL-protected Mack engine in this 1990 truck was as wear-free as an engine in comparable service treated to TWENTY TIMES the oil changes.

The 1990 Mack truck that ran 409,000 miles without an oil change on AMSOIL
Haywood Gray's 1990 Mack E7-400.

Colonial Heights, Virginia — "I didn't see any surprises in there at all," said owner/operator Haywood Gray of his 1990 Mack E7-400 engine at teardown, after Gray had run the engine 409,000 miles without once changing the oil.

The AMSOIL Setup

Gray used AMSOIL Synthetic 15W-40 Heavy Duty Diesel and Marine Oil, an AMSOIL By-Pass Filter and periodic oil analysis to achieve his impressive drain interval.

When the E7-400 was torn down by the local Mack dealership and its parts were examined by a certified independent engine rater, it showed only light to moderate wear throughout.

Graph of iron wear readings from the Mack engine teardown
Iron wear — the AMSOIL-protected engine.
Graph of lead wear readings from the Mack engine teardown
Lead wear — the AMSOIL-protected engine.

In fact, according to the engine rater, the parts could have been put right back in the engine. "I see no reason why the engine couldn't run on," he said.

Oil Analysis Confirms the Findings

The teardown oil analysis confirmed the rater's findings. The sample's content of wear metals was extremely low — one-sixth the lead and one-third the iron allowed by Mack condemnation limits — after 409,000 miles without an oil change.

The oil analysis findings report showing low wear metals after 409,000 miles
The oil analysis findings.